Compound structure of mid-sole and insole

ABSTRACT

A compound structure of mid-sole and insole is disclosed. A PU outer sole is made into a trough shape in order to reduce the use of PU and thus the weight thereof. The mid-sole and insole are made as a compound of a lightweight material, such as EVA, and disposed inside the trough. The invention thus provides best comfort to the user while the total weight of shoe is effectively reduced.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to a light shoe and, in particular, to a compoundstructure of mid-sole and insole. Not only is the total weight of thedisclosed shoe reduced, it also provides best comfort to the user invibration absorption.

2. Related Art

According to researches of the American Podiatric Medical Association,the reaction imposed on the feet during normal walking is about 1.5 to 2times the body weight. It is as much as 2 to 3 times the body weightduring running. Therefore, the people often feel fatigue and pain in thefeet. In the long run, there can be damages to knees, waist and evenspine.

To reduce the burden on feet during walking or running, the concept of‘lightweight shoe’ has become popular in the industry of shoes.

For example, ROC Pat. No. M317186 discloses a lightweight shoe. Therecess part of the outer sole is provided with an air pad so that theshoe is largely reduced in its weight. The surface of the air pad iswavy. The hollow interior is filled with air. When a foot rests on theair pad, the enclosed air makes the air pad elastic and evenlydistributes the force on the foot bottom.

SUMMARY OF THE INVENTION

According to the disclosed compound structure of mid-sole and insole,the solid PU outer sole with the density of about 0.6 is made into atrough shape. This reduces the use of material in the bottom and thusthe weight thereof. The mid-sole and insole are made of EVA with thedensity of 0.2 into a compound, and disposed in the trough. Differentblocks of the compound are formed from EVA of different hardnesses andproperties. Not only is the total weight of shoe effectively reduced toachieve the design of a ‘lightweight shoe’, the invention also providesbest comfort to the user.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the invention willbecome apparent by reference to the following description andaccompanying drawings which are given by way of illustration only, andthus are not limitative of the invention, and wherein:

FIG. 1 is a three-dimensional exploded view of the invention; and

FIG. 2 is an assembly view of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings,wherein the same references relate to the same elements.

FIG. 1 is a three-dimensional exploded view of the invention. FIG. 2shows the assembly of the invention. The outer sole 1 is made of PU witha density of about 0.6 into a trough 11. A mid-sole 2 and an insole 3made of EVA with a density of about 0.2 are integrally formed orattached together to form a compound, which is disposed in the trough 11of the outer sole 1. Since EVA has the good features of being soft,weather-tolerant, elastic, chemical-tolerant, and easy to dye, it iswidely used in shoe materials.

In order to support the insole 3, the mid-sole 2 is made of EVA or themixture of EVA and corkwood, with a hardness between 65 and 70.

The surrounding frame 31 of the insole 3 provides appropriate wrappingfunction to the foot. To prevent deformation, it is made of EVA with ahardness between 50 and 55.

The insole body 32 directly in touch with the foot has to havesufficient elasticity in order to provide best comfort to the user. Itis made of elastic EVA with a hardness between 40 and 45.

The area corresponding to the inner side of the forefoot on insole body32 is set as a vibration absorption area 33. A vibration absorptionmaterial is used to reduce the pressure imposed on the foot. Thevibration absorption area 33 is made of vibration-absorbing EVA with ahardness between 40 and 45.

According to the invention, the solid PU outer sole with a density of0.6 is made into a trough. The material used in and thus the weight ofthe PU outer sole are significantly reduced. The mid-sole and insole areformed into a compound with a density of 0.2. The compound is disposedin the trough of the outer sole. Different blocks of the compound areintegrally formed from EVA of different hardnesses and properties. Notonly is the total weight of the disclosed shoe reduced, it also providesbest comfort to the user in vibration absorption.

Although the invention has been described with reference to specificembodiments, this description is not meant to be construed in a limitingsense. Various modifications of the disclosed embodiments, as well asalternative embodiments, will be apparent to persons skilled in the art.It is, therefore, contemplated that the appended claims will cover allmodifications that fall within the true scope of the invention.

What is claimed is:
 1. A compound structure of mid-sole and insoledisposed in a trough formed on an outer sole, the compound structurebeing made of a lightweight material to reduce the total weight of ashoe and to provide comfort by absorbing vibrations.
 2. The compoundstructure of mid-sole and insole of claim 1, wherein he material of theouter sole is PU with a density of about 0.6.
 3. The compound structureof mid-sole and insole of claim 1, wherein the lightweight material ofthe mid-sole and insole is EVA with a density of about 0.2.
 4. Thecompound structure of mid-sole and insole of claim 3, wherein themid-sole is made of EVA or a mixture of EVA and corkwood with a hardnessbetween 65 and
 70. 5. The compound structure of mid-sole and insole ofclaim 3, wherein the surrounding frame of the insole is made of EVA witha hardness between 50 and
 55. 6. The compound structure of mid-sole andinsole of claim 3, wherein the insole body is made of elastic EVA with ahardness between 40 and
 45. 7. The compound structure of mid-sole andinsole of claim 3, wherein the area of the insole body corresponding tothe inner side of the forefoot is made of vibration-absorbing EVA with ahardness between 40 and 45.